1. Field
This disclosure relates to bundle adjusting images.
2. Background
Applications can use multiple photographic images of a geographic area to create or update a three-dimensional (3D) representation of the area and of particular structures and other points of interest in that geographic area. For example, oblique imagery of a city area taken from an aircraft may be used to generate a three-dimensional view of city streets, buildings, and other points of interest. In general, multiple images from a set of oblique images overlap an area. In order for these multiple images to be used in generating an accurate representation of the area in 3D, the images are “bundle adjusted.” Bundle adjusting is a technique of determining camera parameters for individual images so that the objects in the images are accurately represented in a corresponding 3D representation. Bundle adjusting imagery over a large area, such as that performed for map and geographic imagery applications, can be highly resource intensive.
As the use of such applications becomes more frequent, the scope (e.g., the size of the geographic area to which the bundle adjustment applies) and the frequency of updates of such geographic representations increase, and, as a result, impose a heavy processing burden. Bundle adjusting is, therefore, often performed in a distributed manner across several processing nodes of a network. In one approach, a group of overlapping or adjacent images is assigned to each processing node, and their individual results are combined.
However, for reasons including the propagation of the effect of a bundle adjustment in one subarea to other parts of the coverage area through overlapped images and the like, calculating bundle adjustments separately for different areas may result in inaccuracies.